Understanding the Risk Factors for Bloat in Dogs
Gastric dilatation-volvulus, commonly referred to as GDV or “bloat”, is a common cause of death for several large and giant breeds. It is a life-threatening disorder and if left untreated, results in death.
Bloat occurs when the stomach fills with food, water and/or gas. This results in increased pressure that enlarges and compresses the stomach and eventually causes the stomach to rotate or twist into an abnormal position. When the stomach twists, it actually crimps the inflow and outflow of gastric contents and blood to and from the stomach. This in turn cuts off the blood supply to the organ causing a cascade of events that can eventual cause death. Approximately 30 percent of dogs that develop bloat die or have to be euthanized.
Common signs of “bloat” include excessive drooling and unproductive vomiting. Because the stomach is twisted, the esophagus (the tube that goes to/from the stomach) is crimped; the dog cannot productively vomit or swallow their saliva. The abdomen expands and gets very distended. The abdominal expansion is more obvious in some dogs than others depending on their confirmation because some large deep-chested dogs may have a large portion of their stomachs under their rib cage which makes the distention less obvious. Dogs are often restless and uncomfortable as this is a very painful condition.
Breeds thought to be at high risk include: Akita, bloodhound, collie, Great Dane, Irish setter, Irish wolfhound, Newfoundland, rottweiler, Saint Bernard, standard poodle and Weimaraner.
Risk Factors for Canine Bloat
Dr. Larry Glickman, an epidemiologist at the Purdue University School of Veterinary Medicine, conducted a study on canine bloat, where he followed over 1,900 dogs to help identify risk factors. Risk factors include:
The dogs with the greatest risk of developing bloat have deep narrow chests. Breeds at highest risk for bloat include the Great Dane, Bloodhound, standard Poodle, Irish wolfhound, German Shepherd Dog, Irish setter, Akita, and Boxer. All other deep-chested breeds and deep-chested mixed-breed dogs are also at higher risk.
The risk of bloat is slightly higher in males than females.
Lean dogs were also found to be at higher risk for developing bloat than overweight dogs. It is unknown why, but some believe it is because fat takes up space in the abdomen allowing less space for the stomach to “rotate” or move around.
Older dogs are at a higher risk. Some believe that the ligaments that holds the stomach in its normal position stretches with age causing an increased risk. The risk of developing bloat goes up 20 percent each year after the age of 5 in large breed dogs and it goes up 20 percent each year after the age of 3 in giant breed dogs.
Dogs with relatives that have developed bloat are at higher risk. Dogs with parents or siblings that have experienced bloat are at 60% at higher risk for developing bloat themselves.
Fast eaters are at higher risk for developing bloat. Many believe this is due to increased swallowing of air when eating fast.
Elevated food bowls have been shown to increase the risk of bloat. This has been a previously thought “preventative”.
Dogs with nervous, fearful, or aggressive personalities have a higher incidence of bloat.
Stress, such as that occurs during kenneling, is an important precipitating factor.
Dogs fed dry food only or fed one large daily meal where at a higher risk for bloat. The theory is that the stomach is weighed down and maximally stretched during the one large meal.
Dogs fed foods in which an oil or fat ingredient, such as sunflower oil or animal fat, were listed among the first four ingredients. This was associated with a 2.4-fold increased risk of GDV.
Most cases of bloat occur after 6 pm.
Several previously popular theories regarding the risk factors for bloat were not substantiated during Dr. Glickman’s study. There was no correlation of bloat risk to exercise before or after eating or to the timing or volume of water intake before or after eating. There was also no correlation of bloat to vaccinations or to a particular brand of food. In a newer study published in January/February 2006 issue of the Journal of the American Animal Hospital Association (JAAHA), also found ” Neither an increasing number of animal-protein ingredients nor an increasing number of soy and cereal ingredients among the first four ingredients significantly influenced GDV risk.”
Treatment for Canine Bloat
It is important that dogs showing signs of bloat be taken immediately to a veterinary for emergency care. Treatment generally includes intravenous fluids to treat shock, decompression of the stomach with either a stomach tube or by use of a hypodermic needle that enters the stomach through the side of the abdomen, can help relieve the pressure. Emergency surgery is then recommended to evaluate the health of the stomach and to return it to its normal position. Once the stomach is evaluated and returned to the normal position, a “gastropexy” is done. A gastropexy secures the stomach to the body wall to help prevent future episodes of bloat. Some dogs may also require removal of a damaged portion of the stomach wall or a damaged spleen. With early diagnosis and prompt treatment, approximately 80% of dogs with GDV will live.
Prevention of Bloat
There is much to still be learned about the causes and the best methods to prevent bloat. The following are current thoughts on the best methods for prevention:
Divide meals into 2 or 3 meals per day rather than one large meal. Feed a mixture of canned food and dry food. Avoid elevated feeders. Any diet changes should be made gradually over a period of 3 – 5 days. Feed susceptible dogs individually and if possible, in a quiet location.
In breeds that are at high risk, discuss the pros and cons of having a preventative gastropexy with your regular veterinarian. This surgery is commonly performed at the time of neutering.
You may want to consider avoiding foods in which oil or fat is listed as the first four ingredients. This was associated with a higher risk of bloat, however, it is not clear whether a diet low in oil or fat content is protective.
When buying a dog, ask about family history of bloat and stay away from breed lines with a prominent history.
Make sure the dog sitter or kennel pays special attention for breeds at risk. Make sure they understand signs of bloat and have your permission to take them to an emergency center for treatment if signs occur. Consider having a house sitter rather than a kennel or whatever is least stressful to an older deep-chested dog at high risk for bloat.
Although this was not identified as a risk factor in the mentioned study, most veterinarians still recommend that water is available to dogs at all times, but do limit the amount immediately after eating if the dog appears to over-consume. Many also recommend that you avoid vigorous exercise, excitement, and stress one hour before meals and two hours after meals. Slow walks are permissible, as it may help stimulate normal gastrointestinal function.
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